1. Field Of The Invention
The present invention relates to a forced recirculation type steam-generating apparatus, or more in particular to a method of preventing the recirculation pump cavitation which otherwise might occur in the recirculation pump when the pressure in the steam-generating section of the reactor or a circulation type boiler is steeply reduced and the forced recirculation type steam-generating apparatus using the same method.
2. Description Of The Prior Art
In the conventional reactor and the like, the cavitation in the recirculation pump and jet pump has been prevented by a method of detecting the reduction of water supply, thus generating a cavitation preventing signal, by the use of which the recirculation flow is reduced or another method of monitoring the difference in temperature between the main steam and the recirculation water, thus generating a cavitation preventing signal, when the temperature difference is reduced below a predetermined value, by the use of which the recirculation flow is reduced. In the former method, the cavitation is likely to occur due to the steep pressure reduction caused by the trouble of the pressure control device. The latter method, on the other hand, has the disadvantage that the response of the detector for detecting the temperature of the main steam line is so slow that the operation for reducing the recirculation flow is delayed at the time of steep pressure drop in the reactor, thus providing unsatisfactory means for preventing the recirculation pump cavitation.